refactor: Move git version info gather in into a build script

src/build_metadata/build.rs

@@ -0,0 +1,92 @@
+use std::process::Command;
+
+fn run_git_command(args: &[&str]) -> Option<String> {
+	Command::new("git")
+		.args(args)
+		.output()
+		.ok()
+		.filter(|output| output.status.success())
+		.and_then(|output| String::from_utf8(output.stdout).ok())
+		.map(|s| s.trim().to_owned())
+		.filter(|s| !s.is_empty())
+}
+fn get_env(env_var: &str) -> Option<String> {
+	match std::env::var(env_var) {
+		| Ok(val) if !val.is_empty() => Some(val),
+		| _ => None,
+	}
+}
+fn main() {
+	// built gets the default crate from the workspace. Not sure if this is intended
+	// behavior, but it's what we want.
+	built::write_built_file().expect("Failed to acquire build-time information");
+
+	// --- Git Information ---
+	let mut commit_hash = None;
+	let mut commit_hash_short = None;
+	let mut remote_url_web = None;
+
+	// Get full commit hash
+	if let Some(hash) =
+		get_env("GIT_COMMIT_HASH").or_else(|| run_git_command(&["rev-parse", "HEAD"]))
+	{
+		println!("cargo:rustc-env=GIT_COMMIT_HASH={hash}");
+		commit_hash = Some(hash);
+	}
+
+	// Get short commit hash
+	if let Some(short_hash) = get_env("GIT_COMMIT_HASH_SHORT")
+		.or_else(|| run_git_command(&["rev-parse", "--short", "HEAD"]))
+	{
+		println!("cargo:rustc-env=GIT_COMMIT_HASH_SHORT={short_hash}");
+		commit_hash_short = Some(short_hash);
+	}
+
+	// Get remote URL and convert to web URL
+	if let Some(remote_url_raw) = get_env("GIT_REMOTE_URL")
+		.or_else(|| run_git_command(&["config", "--get", "remote.origin.url"]))
+	{
+		println!("cargo:rustc-env=GIT_REMOTE_URL={remote_url_raw}");
+		let web_url = if remote_url_raw.starts_with("https://") {
+			remote_url_raw.trim_end_matches(".git").to_owned()
+		} else if remote_url_raw.starts_with("git@") {
+			remote_url_raw
+				.trim_end_matches(".git")
+				.replacen(':', "/", 1)
+				.replacen("git@", "https://", 1)
+		} else if remote_url_raw.starts_with("ssh://") {
+			remote_url_raw
+				.trim_end_matches(".git")
+				.replacen("git@", "", 1)
+				.replacen("ssh:", "https:", 1)
+		} else {
+			// Assume it's already a web URL or unknown format
+			remote_url_raw
+		};
+		println!("cargo:rustc-env=GIT_REMOTE_WEB_URL={web_url}");
+		remote_url_web = Some(web_url);
+	}
+
+	// Construct remote commit URL
+	if let Some(remote_commit_url) = get_env("GIT_REMOTE_COMMIT_URL") {
+		println!("cargo:rustc-env=GIT_REMOTE_COMMIT_URL={remote_commit_url}");
+	} else if let (Some(base_url), Some(hash)) =
+		(&remote_url_web, commit_hash.as_ref().or(commit_hash_short.as_ref()))
+	{
+		let commit_page = format!("{base_url}/commit/{hash}");
+		println!("cargo:rustc-env=GIT_REMOTE_COMMIT_URL={commit_page}");
+	}
+
+	// --- Rerun Triggers ---
+	// Rerun if the git HEAD changes
+	println!("cargo:rerun-if-changed=.git/HEAD");
+	// Rerun if the ref pointed to by HEAD changes (e.g., new commit on branch)
+	if let Some(ref_path) = run_git_command(&["symbolic-ref", "--quiet", "HEAD"]) {
+		println!("cargo:rerun-if-changed=.git/{ref_path}");
+	}
+
+	println!("cargo:rerun-if-env-changed=GIT_COMMIT_HASH");
+	println!("cargo:rerun-if-env-changed=GIT_COMMIT_HASH_SHORT");
+	println!("cargo:rerun-if-env-changed=GIT_REMOTE_URL");
+	println!("cargo:rerun-if-env-changed=GIT_REMOTE_COMMIT_URL");
+}